Hi Michel,
On Thu, May 31, 2018 at 11:11 AM, M P <buserror@xxxxxxxxx> wrote:
> On Fri, 25 May 2018 at 11:31, Geert Uytterhoeven <geert@xxxxxxxxxxxxxx>
> wrote:
>> On Thu, May 24, 2018 at 11:28 AM, Michel Pollet
>> <michel.pollet@xxxxxxxxxxxxxx> wrote:
>> > This adds the constants necessary to use the renesas,r9a06g032-sysctrl
> node.
>> > @@ -0,0 +1,187 @@
>> > +/* SPDX-License-Identifier: GPL-2.0 */
>> > +/*
>> > + * R9A06G032 sysctrl IDs
>> > + *
>> > + * Copyright (C) 2018 Renesas Electronics Europe Limited
>> > + *
>> > + * Michel Pollet <michel.pollet@xxxxxxxxxxxxxx>, <buserror@xxxxxxxxx>
>> > + * Derived from zx-reboot.c
>> > + */
>> > +
>> > +#ifndef __DT_BINDINGS_R9A06G032_SYSCTRL_H__
>> > +#define __DT_BINDINGS_R9A06G032_SYSCTRL_H__
>> > +
>> > +#define R9A06G032_CLKOUT 0
>> > +#define R9A06G032_CLK_PLL_USB 1
>> > +#define R9A06G032_CLK_48 1 /* AKA CLK_PLL_USB */
>> > +#define R9A06G032_CLKOUT_D10 2
>> > +#define R9A06G032_CLKOUT_D16 3
>> > +#define R9A06G032_MSEBIS_CLK 3 /* AKA CLKOUT_D16 */
>> > +#define R9A06G032_MSEBIM_CLK 3 /* AKA CLKOUT_D16 */
>> > +#define R9A06G032_CLKOUT_D160 4
>> > +#define R9A06G032_CLKOUT_D1OR2 5
>> > +#define R9A06G032_CLK_DDRPHY_PLLCLK 5 /* AKA CLKOUT_D1OR2 */
>
>> [...]
>
>> I have 3 comments:
>
>> 1. I had expected this list to match (both name- and order-wise)
> Appendix
>> C ("Clock Tree Structure") in the RZ/N1[DSL] User’s Manual: System
>> Introduction, Multiplexing, Electrical and Mechanical Information.
>> That would make it easier to review.
>
> Well, that document was made a *long* time after the internal documentation
> we used to generate the clock lists. There are a few things we had to do:
>
> * Renumber peripherals. We decided a long time ago that u-boot and linux
> would stick to zero based peripherals, and not one based numbers. It's next
> to impossible to keep mixing number based across software base, so we use
> UART0 while the hardware manual mentions UART1 -- It *is* documented
> extensively with out SDK, and makes life using linux a lot easier. It's
> across all our SDK, u-boot, webapps readmes, howtos etc.
>
> * Rename some peripherals. Plenty of peripherals names made little sense
> and had zero consistency, in fact, many names were different depending on
> the place they were used! -- "flashnand"+"nand_flash"+"FNAND" etc,
> "QUADSPI"+"QSPI" etc etc so we also re-normalized the names to match linux
> conventions.
>
> * Other internal reasons I can't document here
>
> Also, the value here are made up anyway -- so I've decided to sort them to
> make sure any clock that has a parent is numbered *after* the parent...
Well, all of that combines makes it very hard for us to review the list.
>> 2. These definitions seems to be a mix of:
>> 1. Internal core clocks,
>> 2. Other core clocks,
>> 3. Module clocks.
>
>> The internal clocks do not need to be referenced from DT, so I would
>> not make them part of the DT bindings.
>
> Why? I'm told that "Bindings aren't for linux" -- why can't I imagine
> 'something' needing them? Why would I decide NOT to include them,
> as they are there? I 'factored' a few of them to the same number when
Just general safety w.r.t. unchangeable DT definitions: anything that is
not listed here cannot be declared wrong later.
> applicable.
You're 100% sure they're the same?
> This is all done automatically BTW -- a script takes the original clocking
> spreadsheet, and converts it into a table, correcting 'human input' as it
> goes along.
So the internal spreadsheet doesn't match the public documentation neither?
>> 3. It looks like the module clocks can be referred to by register offset
>> and bit position, which is similar to how this is handled on R-Car
>> SoCs.
>> Perhaps you can just drop the definitions for these from the header
>> file, and refer to them by (combined) register offset and bit
> position
>> instead?
>> Or am I missing something?
>> I believe this can also be done for the module resets (later).
>
> If you look in the .c file, you'll see that most gate have not just one
> register/bit pair associated with them -- there are several, spread
> across registers.. Also, there are clocks in there with two gates,
> or none. Given that, I've decided a separate numbering
> made sense.
OK, fair enough.
Gr{oetje,eeting}s,
Geert
--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx
In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds
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